Stringer foundation for slide fastener

ABSTRACT

A stringer foundation for a slide fastener has a pair of parallel tapes which have been simultaneously formed on a warpknitting machine with a connecting filament joining their confronting edges. Each tape is formed by a plurality of warp chains laterally interconnected by laid-in weft filaments which span at least three of the wales formed by the chains. The connecting filament can be tensioned tighter than either the warp or weft filaments to form openings adjacent the edge wale. The connecting filament is adapted to be removed after mounting of the coupling elements.

[ Sept. 11, 1973 Waited States Patent [1 1 Friihlich et a1.

B .TTX 14 66 /8 77 6 02/ /2 88 9 22 3 .6 l2 W s N O I T A C I L P P u IA mmmR m sl m m m T HJ FWL W T 5690 57 A 5457654 F 9999999 HHHHHHH N l E8950099 R 967 847 0 ,5. F 6537963 09086 3 ,3 2223222 .m y e n w mh E C Dn m l mmG m L LE r S m h R flm G 0 8&3 u M Em A 0 m l h n T t .l A u m mD 0y N wea U nP m 0 OD. fir. F harm p6 RR ACS 06 G m m N t n .lT n g R 8M TA m s SF 1 A l l l 4 5 3 5 7 7 612,495 11/1948 Great Britain 28/76 T6,513,284 4/1966 Netherlands..........................66/193 [22] Filed:Oct. 20, 1970 Appl. No.: 82,323

Primary Examiner-James Kee Chi AttorneyKarl F. Ross [30] ForeignApplication Priority Data [57] ABSTRACT A stringer foundation for aslide fastener has a pair of Apr. 4, 1970 Germany................... P20 16 139.1

[52] US. 66/193, 66/202, 24/205.l6,

parallel tapes which have been simultaneously formed on a warp-knittingmachine with a connecting filament joining their confronting edges; Eachtape is formed by a plurality of warp chains laterally interconnected bylaid-in weft filaments which span at least three of the wales formed bythe chains. The connecting filament 0 6S 2 m n 91.182 10, 2 090R, 4. 2 S4 C A31 1 ,95 b o H6Q 64 Q 2 2R New 0 .4 D "8 36 1 N "16 2 bm 4r 0% S5 11 dWO d62 .1 MP ll 8 55 can be tensioned tighter than either the warp orweft filaments to form openings adjacent the edge Wale. The connectingfilament is adapted to be removed after mounting of the couplingelements.

[56] References Cited 7 UNlTED STATES PATENTS 2,652,705 9/1953Weinberg........... 3,570,482 3/1971 Emoto et al.......

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STRINGER FOUNDATION FOR SLIDE FASTENER l. FIELD OF THE INVENTION Thepreset invention relates to a stringer foundation for a slide fastener.

2. BACKGROUND OF THE INVENTION Such a foundation is usually made oftapes woven separately on a single loom and then paired prior toattachment of the coupling elements. Since, as the loom operates, thevarious tensions inevitably Change, the tapes always have differentcharacteristics-elasticity, thickness, width, rigiditythroughout theirlength. Thus, in the finished stringer confronting sections of tape areoften different, resulting in a fastener whose tolerances are low andwhich is difficult to attach to a garment.

It is further quite an expensive process to weave a thin band for such astringer foundation, while subdividing a uniform wide band is notpossible since the support tapes must be neatly selvedged.

In the commonly assigned co-pending application Ser. No. 52,377 filed 2July 1970 by Alfons Frohlich and Karl Rohn and entitled METHOD OF ANDAP- PARATUS FOR MAKING SLIDE-FASTENER STRINGERS now US. Pat. No.3,633,528 a method is disclosed wherein two coils are fed to a sewingapparatus in an interleaved condition, are separated upstream of thesewing station, and are interleaved together again just downstream ofthis sewing station, i.e.,

after being sewn onto respective support tapes.

All of these steps are carried out simultaneously and continuously. Insuch a manner, the spacing between adjacent coil turns is carefullymaintained the same since these coils are left interleaved up to thelast possible instant before sewing, so that the finished slidefastenerassembly will not buckle or how. At the same time the full turn isexposed under the sewing needle so that the sewing operation can becarried out at high.

3. OBJECTS OF THE INVENTION An object of the present invention is animproved slide-fastener stringer foundation.

Another object is to advance the principles set forth in the above-citedpatent application.

Yet another object is to provide a stringer foundation to which it iseasy to attach a pair of coupling elements, while the tapes areidentical in their various characteristics on both sides of thesecoupling elements.

4. SUMMARY OF THE INVENTION The above objects are obtained, according tothe present invention, by a stringer foundation for a slide fastenercomprising a pair of selvedged warp-knit parallel support tapes whoseconfronting edges are joined together by a removable connecting filamentpassing back and forth between them.

The tapes are identical in neighboring sections, on each side of thecoupling elements, since they are knit simultaneously and are heldtogether by the removable connecting filament. Feeding of the two joinedtapes to the sewing station, where they are separated immediately beforeor after the attachment of the coupling elements, becomes an extremelysimple operation since only a single tape, in effect, need be guided;

In accordance with other features of the present invention the edges ofthe tapes are reinforced, either by doubling or tripling the yarn or byusing bulk yarn, to make the tapes as thick at these edges as they arein the center, since some of the laid-in weft filaments much be left outadjacent the tape edges to make a neat selvedge. It is also possible toset partially one of the guide bars of the circular, flat-bed or Raschelknitting machine to leave out weft filaments in the center so that thefinished tapes are of regular cross-sectional thickness.

The weft filaments, according to another feature of this invention, arelaid in and have a weft reach (the number of wales spanned) of at leastthree, and preferably four, wales while the connecting filaments have areach of two or four wales.

Another feature of the invention is that the connecting filament istensioned tighter than the other filaments so that the edge wales ofeach tape at their confronting edges are compressed and pulled from therest of the tapes to enlarge the adjacent valley and form a series ofopenings through the tapes. These openings serve to accommodate thestitching that holds the coupling elements to the tapes so that it neednot pass through and damage other filaments, or the coupling heads ofthe coils can be simply forced therethrough to anchor them. Cutting ofthe connecting filamentafter attachment of the coupling elements causesthese openings to shrink and the tapes to fold back.

According to a further feature of this invention, the connectingfilament has a lower melting temperature than the other tape-formingfilaments so that a subsequent thermofixing process melts it. It canalso be made of some material which is dissolvable in a bath. 7

In our concurrently filed and commonly assigned application Ser. No.82,327 there is disclosed a slidefastener stringer comprising a pair ofelongated warpknit support tapes having confronting longitudinal edges,each tape being constituted of a plurality of transversely offsetlongitudinally extending warp chains and laid-in weft filamentstransversely connecting the chains to form a warp-knit foundation, andrespective elongated continuous coupling elements interconnectable uponmovement of a slider therealong and lying along the confronting edgesand secured thereto.

In such a stringer the weft filament islaid in with'a 4-4/0-0 patternand the warpfilament is chained in a O-l/l-O pattern, or a 2-0/0-2pattern, or a pair of such warp filaments are provided, one chained in aO-l/l-O pattern and the other in a 2-0/0-2 pattern.

The tapes of this stringer are formed with stitching holes forattachment of the coupling elements and its weft filaments arevoluminous textured (bulk) yarn.

That application also discloses a method of making a slide-fastenerstringer comprising the steps of forming a plurality of transverselyoffset longitudinally extending warp chains, laying into these chains aplurality of weft filaments to form a pair of warp-knit foundationtapes, securing an elongated coupling element to the confronting edgesof the tapes, and thermally fixing the tapes.

Our commonly filed and assigned application Ser. No. 82,326 discloses aslide-fastener stringer comprising a pair of interengageable couplingelements each having a multiplicity of turns, a pair of warp-knitsupport tapes having Wale-forming warp filaments and course-forming weftfilaments, and a succession of stitches passing between the turns andthrough the tapes and securing the elements to the confronting edges ofthe tapes, the stitches having a stitch length greater than the coursewidth. These stitches pass through the tapes between the wales, and thestitch length is an integral multiple of the course width, e.g., equalto twice the course width. The weft filaments are laid in a 4-4/0-0pattern and at least some warp filaments are chained in a l/l-O patternwhile other warp filaments are chained in a 2-0/0-2 pattern. The warpand weft filaments are of greater bulk adjacent the edges than remotetherefrom. The wales are on one face of the tapes, the other face beingsmooth and engaging the coupling elements.

Our commonly filed and assigned application Ser. No. 82,325, now US.Pat. No. 3,685,474 discloses a method of making a slide-fastenerstringer comprising the steps of simultaneously forming a pair ofparallel fabric tapes and joining same together at their confrontingedges by at least one connecting filament, thereafter simultaneouslyattaching one of a pair of interengageable coupling elements to each ofthe confronting edges, and breaking the connecting filament to separatethe tapes. These tapes are warp knit by forming a plurality oflongitudinally extending Wale-forming warp chains from a plurality ofwarp filaments and laying into the chains a plurality of course-formingweft filaments. The weft filaments are spanned across at least threewales and the tapes are also knit with second warp filaments chained inopposition to the first warp filaments while at least one of thefilaments which comes to the edge of the tapes is reinforced.

That application also describes a method as above with the additionalstep of tensioning the connecting filaments more tightly than the warpand weft filaments to form a succession of openings in the tapes betweenthe wales adjacent the confronting edges, whereby breaking theconnecting filament separates the tapes and substantially closes theopenings. The elements are attached by sewing with stitches passingthrough the openings, or the elements are attached to the tapes bypassing their coupling heads through the openings. The connectingfilament may be spanned over only two courses so that the openings areformed adjacent the edge wales of the tapes. Four such tapes can be knitinterconnected by three such connecting filaments, the

' method then further comprising the step of cutting the centralfilament prior to attachment of two pairs of intercngageable couplingelements to the two joined pairs of tapes thus formed. 7

Our concurrently filed and commonly assigned patent application Ser. No.82,324 discloses a slidefastener stringer comprising a pair ofinter-engageable coupling elements, a pair of parallel warp-knit supporttapes each having longitudinally extending parallel wales including atleast one wale defining a band along the edge of the tape separated fromthe rest of the wales by a valley, and respective rows of stitching eachengaging over one of the elements and passing through the respectivetape only in its valley for securing the elements to the tapes. In sucha stringer the edge band is formed by a single wale constituted largelyfrom a reinforced warp filament, or it can be formed by a pair of wales.The stringer of that application can have a connecting filamentextending between the edge bands of the pair of tapes and tensioned tobroaden the valleys, thereby facilitating stitching of the elements tothe tapes. The tapes each have a smooth face, with the elements attachedto the smooth faces.

5. DESCRIPTION OF THE DRAWINGS The above and other objects, features,and advan tages will become apparent from the following description,reference being made to the drawing, in which:

FIGS. 1, 2 and 3 show the combined notation for three embodiments of theknit according to the present invention;

FIG. 4A is a diagram showing the guide-bar movement for producing theknits of FIGS. 1 and 3;

FIG. 4B is a diagram showing the threading of a knitting-machine guidesfor producing the knits of FIG. 1;

FIGS. 5 and 6 show the combined notation of fourth and fifth embodimentsof the knit according to the present invention;

FIG. 7 is a cross section through a slide-fastener stringer according tothe present invention; and

FIG. 8 is a sixth embodiment of the knit according to the presentinvention.

6. SPECIFIC DESCRIPTION To fully appreciate the structure of the knits,it is necessary to understand the notation of FIGS. 1 6 and 8.

FIGS. 1, 2, 3, 5, and 6 and 8 represent standard tricot point papernotation wherein each dot stands for a needle. The vertical rows of dotssymbolize the wales and the horizontal rows symbolize the courses. Thelines passing around the dots represent the paths of the guides duringknitting and, therefore, the pattern of the yarns carried by theseguides. FIG. 4A shows the paths of the individual guides, and FIG. 4Bshows which of the guides are threaded for each row of needles.

Thus, for the knits of interest here two types will be seen. The guidebar can move from one space to another during each knitting cycle, i.e.,the formation of each course, and then move back during the next raisingand lowering of the needles. For example, the figure notation for aguide which moves from space 0 to space 1 during one knitting cycle thenback from space I to space 0 during the next cycle is O-l/l-O, with theslash mark (I) separating the two cycles.

The other type of guide movement of interest is that of laying-in. Inthis case the guides do not move in front of the needles (overlap) butmerely shog back and forth behind the needle hooks between cycles. Thenotation here is similar, so that 4-4 0-0 is the figure notation for aguide which as the needles move up and down for one course, stands inspace 4, and then moves to space 0 where it remains as the next courseis knit. In other words, the first two digits signify the two positionsbetween which the guide reciprocates during one knitting cycle and thesecond two digits indicate the end positions for the next cycle. Afterevery two cycles the movements are repeated. Since for laying-in theguides do not move during the knitting cycles, but between them, on eachside of the slash mark both numbers are the same.

For a more detailed discussion of the above forms of notation referencecan be made to the book Advanced Knitting Principles edited by CharlesReichman (National Knitted Outerwear Association: 1964), chapters 26 and30.

As seen in FIG. 1, a slide-fastener stringer comprises a fabric 1constituted by a pair of tapes 7 and 8 each adapted to carry a nyloncoupling coil 2 (see FIG. 7). Each tape 7, 8 consists of warp yarns 4and 5 and weft yarns 6, and the tapes are temporarily linked at theirconfronting edges by a connecting filament 9.

The short-reach warp yarns 4, as shown in FIG. 4A, are chained by thefourth or front guide bar in a O-l/l-O pattern, whereas the long-reachwarp yarns 5 are chained by one of the middle guide bars in oppositionthereto with a 2-0/0-2 pattern. The connecting filaments 9 are breakableand are laid in with a 2-2/0-0 pattern by one of the back guide barswhereas the weft filaments 6 are laid in parallel thereto with a 4-4/0-0pattern. The finished tapes, thus, have wales 3 separated by valleys ortroughs 1 and courses 15. FIG. 4B shows that the frontmost guide bar isfully set, while the other bars are not, so that two tapes will beselvedged and separate when produced on the same knitting machine as isthe case here. The band 1 thus can be subdivided into a pair of neatselvedged tapes 7 and 8, while the fabric characteristics willautomatically be identical all through the same course 16, that is, onboth sides of the tapes center.

FIG. 1 shows how bulk filaments 6' are used instead of the filaments 6where these run to the edge of the tapes. Instead of simply using abulky or textured yarn, it is also possible to double-thread therespective guide bar. In this manner the tapes are of regular thicknessacross their entire width so that handling of them later presents littledifficulty.

In FIG. 2, a connecting filament 9' is shown which is chained in a2-0/0-2 pattern, rather than simply being laid in. Such a structuremakes for a very stable band I, which here is shown to consist of morethan two tapes 7 and 8. Reinforced warp filaments 4' and 5' are alsoused here where these come to the tape edge.

FIG. 3 shows a pair of tapes 7 and 8 wherein only reinforced warpfilaments 4 and weft filaments 6 are bulkier than the other filaments,in order that the finished tapes have regular cross-sectional thickness.In addition, the connecting filament 9" is laid in with a 4-4/0-()pattern.

In FIG. 5 all filaments which come to the edge of the tapes 7 and 8 arereinforced for greatest strength, much as in FIG. 2, except that theconnecting filament is here laid in with a 2-2/0-0 pattern.

A single tape 7 is shown in FIG. 6 which in its central region does nothave a separate weft filament 6 for each warp filament 4 or 5. In thismanner, the central thickness of the tape 7 is reduced. This effect isachieved by only half setting each of the guides of the first guide bartoward the center of each tape.

FIG. 7 shows how the tapes of FIG. 6 are connected to Nylon coil-typecoupling elements 2. The valley 11' directly adjacent the edge of thetapes 7 and 8 receives stitching 12. The edge wale 3 is thickened, asshown at 10, on account of the reinforced filaments used in itsformation. The edge valley 11' is of relatively large width since theconnecting filament 9 for these tapes 7 and 8 is tensioned more tightlythan the other filaments and therefore pulls the two edge wales 10 awayfrom the rest of their tapes.

In FIG. 8 there are shown a pair of tapes 7 and 8 each of which isformed in two portions 13 and 14, separated by a space formed by leavingout one of the long-reach warps 5 and the short-reach warp 4 one wale infrom this edge. In this manner are formed openings 15 adapted to receivethe coupling heads of a slidefastener coupling element 2 which istherefore fastened to the tape without stitching. The connectingfilament 9 is also tensioned tightly in this case so that, after it hasbeen severed, the holes 15 close up somewhat around the elements.

The connecting filaments9, 9' and 9" are made of an easily dissolvablematerial such as polyvinyl alcohol, so that their removal can be readilycarried out in a bath of water. It is also possible to provideconnecting filaments which have a melting temperature much lower thanthat of the other filaments and the coupling elements so that aftermounting of the coupling elements the connecting filament can be meltedout by a heat-treating or thermofixing process.

We claim:

1. A textile web comprising two unitarily and integrally knitlongitudinally extending slide-fastener support tapes each consisting ofa plurality of longitudinally extending wales formed by at least twowarp threads, a laid-in weft thread, and at least one connectingfilament extending back and forth between the proximal wales of saidtapes and destructible to separate said tapes, at least one of saidthreads being of greater thickness than others of said threads and saidfilament for reinforcing the confronting edges of said tapes along saidproximal wales, whereby said confronting edges are thicker than theremainder of said tapes, said connecting filament being tensionedtighter than said threads to produce a respective valley adjacent eachproximal wale which is substantially broader than the valleys separatingtheir remaining wales.

2. The web defined in claim 1 wherein said laid-in thread extends acrossat least three wales.

3. The web defined in claim 2 wherein said warp threads are laid in aI-O/O-l pattern.

4. The web defined in claim 3 wherein said connecting filament is laidin a 4-4/0-0 pattern. I

5. The web defined in claim 3 wherein said connecting filament follows a2-0/0-2 pattern.

1. A textile web comprising two unitarily and integrally knitlongitudinally extending slide-fastener support tapes each consisting ofa plurality of longitudinally extending wales formed by at least twowarp threads, a laid-in weft thread, and at least one connectingfilament extending back and forth between the proximal wales of saidtapes and destructible to separate said tapes, at least one of saidthreads being of greater thickness than others of said threads and saidfilament for reinforcing the confronting edges of said tapes along saidproximal wales, whereby said confronting edges are thicker than theremainder of said tapes, said connecting filament being tensionedtighter than said threads to produce a respective valley adjacent eachproximal wale which is substantially broader than the valleys separatingtheir remaining wales.
 2. The web defined in claim 1 wherein saidlaid-in thread extends across at least three wales.
 3. The web definedin claim 2 wherein said warp threads are laid in a 1-0/0-1 pattern. 4.The web defined in claim 3 wherein said connecting filament is laid in a4-4/0-0 pattern.
 5. The web defined in claim 3 wherein said connectingfilament follows a 2-0/0-2 pattern.